Respiratory Tracts Flashcards
What are the names of the two respiratory tracts?
Upper respiratory tract
Lower respiratory tract
What makes up the upper respiratory tract?
Nasal cavity, pharynx and larynx. It is located in the head and neck.
What is the larynx?
Voice box
What is the vertebral level of the larynx?
Continuous inferiorly with the trachea at C6.
What makes up the lower respiratory tract?
Trachea, the main/principle/primary bronchi and their branches, the bronchioles and alveoli. Entirely in thorax.
Where does the LRT get motor innervation from?
Sympathetic fibres originating in the upper thoracic spinal levels via pulmonary plexues.
Parasympathetic fibres from the vagus nerve.
Where does the LRT get arterial supply from?
Via bronchial arteries arising from the thoracic aorta and intercostal arteries while the bronchial veins drain to the azygos venous system.
What is the trachea?
Inferior continuation of the larynx at C6 through the thoracic inlet to vertebra T4 where it bifuricates into the left and right main bronchus
What forms the tracheobronchial tree?
The trachea, bronchi and bronchioles
What does the tracheobronchial tree do?
It is a system of airways that allow passage of air into the lungs, where gas exchange occurs.
What is the trachea anterior to?
Esophagus
Where does the trachea recieve sensory innervation from?
Recurrent laryngeal nerve
What provides arterial supply to the trachea?
Tracheal branches of the inferior thyroid artery while venous drainage is via the brachiocephalic, azygos and accessory hemiazygos veins.
Compare the R and L main bronchus
Right main bronchus – wider, shorter, and descends more vertically than its left-sided counterpart.
Describe how the bronchi branch out
The main (primary) bronchi branch into lobar (secondary) bronchi.
The lobar bronchi then bifurcate into several segmental (tertiary) bronchi, each of which supplies a bronchopulmonary segment
What are bronchopulmonary segments?
Bronchopulmonary segments are subdivisions of the lung lobes, and act as the functional unit of the lungs.
Where does the bronchi derive innervation from?
Vagus nerve (CN X)
Blood supply and drainage of branchi
Blood supply to the bronchi is from branches of the bronchial arteries, while venous drainage is into the bronchial veins.
What do bronchioles contain and what do they not.
The smallest airways, bronchioles do not contain any cartilage or mucus-secreting goblet cells.
Instead, surfactant lipoprotein which prevents the walls of the small airways sticking together during expiration.
What are alveoli?
Tiny air-filled pockets with thin walls (simple squamous epithelium), and are the sites of gaseous exchange in the lungs.
What happens to conducting bronchioles?
Conducting bronchioles -> terminal bronchioles -> respiratory bronchioles which are distinguishable by the presence of alveoli extending from their lumens
Name the muscle that completes the tracheal ring
Trachealis muscle
What lie lateral to trachea in the neck?
Common carotoid arteries
What is the nerve lying lateral to the trachea on both sides?
Vagus nerve
What type of cartilage is used in the tracheobronchial tree?
Hyaline cartilage
